import os, sys
import math
import random
import time
import glob
import shutil
import numpy as np
from imageio import imread, imsave
import cv2

import paddle.fluid as fluid

import networks
from util import *
from my_args import args


def infer_engine(model_dir,
                 run_mode='fluid',
                 batch_size=1,
                 use_gpu=False,
                 min_subgraph_size=3):
    if not use_gpu and not run_mode == 'fluid':
        raise ValueError(
            "Predict by TensorRT mode: {}, expect use_gpu==True, but use_gpu == {}"
            .format(run_mode, use_gpu))
    precision_map = {
        'trt_fp32': fluid.core.AnalysisConfig.Precision.Float32,
        'trt_fp16': fluid.core.AnalysisConfig.Precision.Half
    }
    config = fluid.core.AnalysisConfig(os.path.join(model_dir, 'model'),
                                       os.path.join(model_dir, 'params'))
    if use_gpu:
        # initial GPU memory(M), device ID
        config.enable_use_gpu(100, 0)
        # optimize graph and fuse op
        config.switch_ir_optim(True)
    else:
        config.disable_gpu()

    if run_mode in precision_map.keys():
        config.enable_tensorrt_engine(workspace_size=1 << 10,
                                      max_batch_size=batch_size,
                                      min_subgraph_size=min_subgraph_size,
                                      precision_mode=precision_map[run_mode],
                                      use_static=False,
                                      use_calib_mode=False)

    # disable print log when predict
    config.disable_glog_info()
    # enable shared memory
    config.enable_memory_optim()
    # disable feed, fetch OP, needed by zero_copy_run
    config.switch_use_feed_fetch_ops(False)
    predictor = fluid.core.create_paddle_predictor(config)
    return predictor


def executor(model_dir, use_gpu=False):
    place = fluid.CUDAPlace(0) if use_gpu else fluid.CPUPlace()
    exe = fluid.Executor(place)
    program, feed_names, fetch_targets = fluid.io.load_inference_model(
        dirname=model_dir,
        executor=exe,
        model_filename='model',
        params_filename='params')
    return exe, program, fetch_targets


class VideoFrameInterp(object):
    def __init__(self,
                 time_step,
                 model_path,
                 video_path,
                 use_gpu=True,
                 key_frame_thread=0.,
                 output_path='output'):
        self.video_path = video_path
        self.output_path = output_path
        self.model_path = model_path
        self.time_step = time_step
        self.key_frame_thread = key_frame_thread

        self.exe, self.program, self.fetch_targets = executor(model_path,
                                                              use_gpu=use_gpu)
        # self.predictor = load_predictor(
        #     model_dir,
        #     run_mode=run_mode,
        #     min_subgraph_size=3,
        #     use_gpu=use_gpu)

    def run(self):
        frame_path_input = os.path.join(self.output_path, 'frames-input')
        frame_path_interpolated = os.path.join(self.output_path,
                                               'frames-interpolated')
        frame_path_combined = os.path.join(self.output_path, 'frames-combined')
        video_path_output = os.path.join(self.output_path, 'videos-output')

        if not os.path.exists(self.output_path):
            os.makedirs(self.output_path)
        if not os.path.exists(frame_path_input):
            os.makedirs(frame_path_input)
        if not os.path.exists(frame_path_interpolated):
            os.makedirs(frame_path_interpolated)
        if not os.path.exists(frame_path_combined):
            os.makedirs(frame_path_combined)
        if not os.path.exists(video_path_output):
            os.makedirs(video_path_output)

        timestep = self.time_step
        num_frames = int(1.0 / timestep) - 1

        if self.video_path.endswith('.mp4'):
            videos = [self.video_path]
        else:
            videos = sorted(glob.glob(os.path.join(self.video_path, '*.mp4')))

        for cnt, vid in enumerate(videos):
            print("Interpolating video:", vid)
            cap = cv2.VideoCapture(vid)
            fps = cap.get(cv2.CAP_PROP_FPS)
            print("Old fps (frame rate): ", fps)

            times_interp = int(1.0 / timestep)
            r2 = str(int(fps) * times_interp)
            print("New fps (frame rate): ", r2)

            out_path = dump_frames_ffmpeg(vid, frame_path_input)

            vidname = vid.split('/')[-1].split('.')[0]

            tot_timer = AverageMeter()
            proc_timer = AverageMeter()
            end = time.time()

            frames = sorted(glob.glob(os.path.join(out_path, '*.png')))

            img = imread(frames[0])

            int_width = img.shape[1]
            int_height = img.shape[0]
            channel = img.shape[2]
            if not channel == 3:
                continue

            if int_width != ((int_width >> 7) << 7):
                int_width_pad = (
                    ((int_width >> 7) + 1) << 7)  # more than necessary
                padding_left = int((int_width_pad - int_width) / 2)
                padding_right = int_width_pad - int_width - padding_left
            else:
                int_width_pad = int_width
                padding_left = 32
                padding_right = 32

            if int_height != ((int_height >> 7) << 7):
                int_height_pad = (
                    ((int_height >> 7) + 1) << 7)  # more than necessary
                padding_top = int((int_height_pad - int_height) / 2)
                padding_bottom = int_height_pad - int_height - padding_top
            else:
                int_height_pad = int_height
                padding_top = 32
                padding_bottom = 32

            frame_num = len(frames)
            print('processing {} frames, from video: {}'.format(frame_num, vid))

            if not os.path.exists(os.path.join(frame_path_interpolated,
                                               vidname)):
                os.makedirs(os.path.join(frame_path_interpolated, vidname))
            if not os.path.exists(os.path.join(frame_path_combined, vidname)):
                os.makedirs(os.path.join(frame_path_combined, vidname))

            for i in range(frame_num - 1):
                print(frames[i])
                first = frames[i]
                second = frames[i + 1]

                img_first = imread(first)
                img_second = imread(second)
                '''--------------Frame change test------------------------'''
                img_first_gray = np.dot(img_first[..., :3],
                                        [0.299, 0.587, 0.114])
                img_second_gray = np.dot(img_second[..., :3],
                                         [0.299, 0.587, 0.114])

                img_first_gray = img_first_gray.flatten(order='C')
                img_second_gray = img_second_gray.flatten(order='C')
                corr = np.corrcoef(img_first_gray, img_second_gray)[0, 1]
                key_frame = False
                if corr < self.key_frame_thread:
                    key_frame = True
                '''-------------------------------------------------------'''

                X0 = img_first.astype('float32').transpose((2, 0, 1)) / 255
                X1 = img_second.astype('float32').transpose((2, 0, 1)) / 255

                if key_frame:
                    y_ = [
                        np.transpose(255.0 * X0.clip(0, 1.0), (1, 2, 0))
                        for i in range(num_frames)
                    ]
                else:
                    assert (X0.shape[1] == X1.shape[1])
                    assert (X0.shape[2] == X1.shape[2])

                    print("size before padding ", X0.shape)
                    X0 = np.pad(X0, ((0,0), (padding_top, padding_bottom), \
                        (padding_left, padding_right)), mode='edge')
                    X1 = np.pad(X1, ((0,0), (padding_top, padding_bottom), \
                        (padding_left, padding_right)), mode='edge')
                    print("size after padding ", X0.shape)

                    X0 = np.expand_dims(X0, axis=0)
                    X1 = np.expand_dims(X1, axis=0)

                    X0 = np.expand_dims(X0, axis=0)
                    X1 = np.expand_dims(X1, axis=0)

                    X = np.concatenate((X0, X1), axis=0)

                    proc_end = time.time()
                    o = self.exe.run(self.program,
                                     fetch_list=self.fetch_targets,
                                     feed={"image": X})

                    y_ = o[0]

                    proc_timer.update(time.time() - proc_end)
                    tot_timer.update(time.time() - end)
                    end = time.time()
                    print("*********** current image process time \t " +
                          str(time.time() - proc_end) + "s *********")

                    y_ = [
                        np.transpose(
                            255.0 * item.clip(
                                0, 1.0)[0, :,
                                        padding_top:padding_top + int_height,
                                        padding_left:padding_left + int_width],
                            (1, 2, 0)) for item in y_
                    ]
                    time_offsets = [
                        kk * timestep for kk in range(1, 1 + num_frames, 1)
                    ]

                    count = 1
                    for item, time_offset in zip(y_, time_offsets):
                        out_dir = os.path.join(
                            frame_path_interpolated, vidname,
                            "{:0>4d}_{:0>4d}.png".format(i, count))
                        count = count + 1
                        imsave(out_dir, np.round(item).astype(np.uint8))

            num_frames = int(1.0 / timestep) - 1

            input_dir = os.path.join(frame_path_input, vidname)
            interpolated_dir = os.path.join(frame_path_interpolated, vidname)
            combined_dir = os.path.join(frame_path_combined, vidname)
            combine_frames(input_dir, interpolated_dir, combined_dir,
                           num_frames)

            frame_pattern_combined = os.path.join(frame_path_combined, vidname,
                                                  '%08d.png')
            video_pattern_output = os.path.join(video_path_output,
                                                vidname + '.mp4')
            if os.path.exists(video_pattern_output):
                os.remove(video_pattern_output)
            frames_to_video_ffmpeg(frame_pattern_combined, video_pattern_output,
                                   r2)


if __name__ == '__main__':
    predictor = VideoFrameInterp(args.time_step, args.saved_model,
                                 args.video_path, args.output_path)
    predictor.run()
